Transaction terminals are in use today at the point of sale in large and small retail stores, restaurants, and the like. Most of the terminals have a card reading capability for acquiring both debit and credit card data. Typically, the card is drawn through a slot in the terminal and the card related data is applied to a microprocessor which identifies the card owner, processes the necessary data to complete the transaction and generates a sale slip. As part of the transaction, the card user is asked to sign his or her name upon a signature capture pad and the signature is electronically recorded as part of the transaction.
The capture pad employed in many point of sale transaction terminals typically includes a glass substrate that is separated from a deformable polyester cover by relatively small non-conductive spheres. The opposing surfaces of the substrate and the cover sheet are coated with a conductive material. The coated surfaces are, in turn, connected to lead lines that surround the capture pad. The lead lines are connected to an x-y register that is arranged to record the signature data and forward the data to a microprocessor. The customer writes his or her signature on the pad using a plastic stylus or a similar instrument having a point which is capable of forcing the conductive surface on the cover sheet at the contact point against the conductive coating upon the substrate thus electronically recording the signature.
Many customers using this type of terminal ignore the plastic stylus and elect instead to write on the capture pad with a writing instrument such as a ballpoint pen or a pencil, which causes rapid deterioration of the pad and eventual destruction of the pad. The pad will also deteriorate in time even when properly used, as the relatively thin cover sheet becomes worn.
Gannon et al. in U.S. Pat. No. 6,572,012 describes a cover assembly for the capture pad of a transaction terminal which protects the capture pad from dirt, dust, and the like.
The Gannon terminal includes a cover for protecting the signature capture pad which includes a first lower panel that contains an open frame that surrounds the capture pad and covers the electrical lead lines that run along the periphery of the capture pad. The lower panel is bonded by adhesive to the terminal housing. The cover further includes an upper cover panel that is placed over the lower cover panel and includes a frame and a protective plastic window that overlies the capture pad. The upper cover panel is removably secured to the lower panel by an adhesive so that the upper panel can be easily replaced if it becomes worn or otherwise damaged.
The Gannon terminal works very well in practice, however, the adhesive holding the upper panel in place can weaken in time and prematurely release the panel. Also, customers tend to tamper with the terminal and find ways to break the adhesive bond between the cover panels. In addition, replacing the upper cover panel can be relatively costly in that not only must the protective film be replaced, but also its frame with the adhesive bonding agent.